SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c2775a120886e393741f75e30e6d46d158e3b1f0f6d0dc594fa26dbf372f76e' 
  AND token = '/9UqzwPDvnj3tX0wHsyKagFbBhjWf+lQ99IpqSqXBl4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}